diff --git a/wasm/vars.go b/wasm/vars.go
index b8c5b6eeb7e2b41bf1cd96ba1af9fb22c9a8035d..9383c8a72b037679927a486836c67244c51c9e81 100644
--- a/wasm/vars.go
+++ b/wasm/vars.go
@@ -5,6 +5,8 @@
 // LICENSE file.                                                              //
 ////////////////////////////////////////////////////////////////////////////////
 
+//go:build js && wasm
+
 package wasm
 
 import (